to the pacific coast of north america by june of next year. >>> international organizations are denouncing a tax on health workers in pakistan this week. the violence put a halt to vaccine work in the country. our reporter in bangkok has more. >>> gunmen shot and killed 12 members of polio vaccination teams in separate incidents around pakistan this week. the united nations is protecting staff members in the country by taking them off duty. the u.n. has responded to the attacks. >> the killing of health workers in pakistan were cruel, senseless and inexcusable acts that i condemn in the strongest of terms. those killed were among thousands across pakistan, especially women who are working selflessly. >> the world health organization is also speaking out against the violence, saying it is depriving the population of potentially life-saving health care. >> irrespective of the circumstances of the situation, attacks on health workers, health facilities or health services are completely unacceptable. >> women health workers held protests in the southern city of karachi and in the capital islamabad.